Labels that are integrated with a mold surface to achieve a desired aesthetic effect are commonly known as “in-mold labels” (IMLs). IMLs are frequently used in the fabrication of molded articles for aesthetic enhancement thereof. Such molded articles are typically consumer products such as cups, containers and complementary items that can be mixed and matched to attain a plurality of aesthetic effects while retaining the functional attributes of the molded articles.
Attempts have been made for optimal positioning of IMLs as surfaces of molded resins that are not readily receptive to other types of decorative application (e.g., paints, inks, decals and the like). For example, U.S. Pat. No. 5,498,307 to Stevenson is directed to a method of in-mold labeling using an adhesive. The method includes forming a pattern structure by applying indicia to a first layer made from a specific plastic material. A clear second layer made from the specific plastic material is applied over the first layer, the first and second layers are bonded. The pattern structure is applied to an interior surface of a mold cavity, and the mold cavity is charged with the specific plastic material. An adhesive retains the pattern structure in the mold cavity. The pattern structure and plastic material are heated, thereby disbursing the plastic material to form a shape of a plastic part. After the plastic part is cooled, the part is removed from the mold cavity with the pattern structure as an integral part of the plastic part.
This method, along with other known methods and devices, anticipates known deficiencies in adhesive systems. It is understood that the placement of a graphic in an inner mold cavity should be consistent to ensure accurate application of the graphic on each molded article. The graphic should not come loose from the mold during the molding process, either as a result of the heating and cooling cycle or as a result of resin abrasion during the molding process. If the graphic wrinkles or curls during the molding process, the molded part will be aesthetically ruined and therefore unfit for commercial sale.
Despite these known methods and devices, adhesive retention of a pattern structure is still required, thereby introducing material and temporal costs into the molding process. Even with adhesive retention, prior approaches dismiss the importance of complete or contoured graphic coverage on a molded article surface and integration of designs for use of the molded article by consumers and potential consumers.
In addition, prior approaches have avoided the application of IMLs to plastic plates, serving dishes, utensils and other complex curved surfaces intended for serving and/or handling food. Typical applications of the IML are made on an essentially flat surface that is eventually sold as a food container (e.g., a yogurt container), or on outer portions of cylindrical containers that have a uniform curvature allowing for the smooth placement of a flat label that may or may not have cut out portions. For products contemplated for food service, however, previous label concepts required pre-folded labels having expensive laminate configurations that are not food-grade quality or are not intended to come into contact with food but instead are applied to the outside of a food container, such as a yogurt cup (see, e.g., the disclosure and discussion at http://www.talkgraphics.com/showthread.php?36444-Creating-labels-for-curved-surfaces). Scored labels also exist, but these are also generally used for applying a label to the outer surface or a cup, cylindrical or polygonal container.
A need therefore persists for improved approaches to graphic labels and their employment in the integration of graphics with molded articles, and particularly molded articles intended for use with food.